Abstract: Given the complexity of Internet macroscopic topology structure, analysis was conducted on the fractal characteristics of Internet topology structure at the router level. Internet topology was divided into different cores based on k-core decomposition. Node number from inner to outer core increased exponentially. Degree distribution in every core showed a high degree of similarity. Analysis was conducted on the spectral density distribution of the graph spectrum of the Internet topology structure. Analysis of the distribution of spectral density and eigenvalues of the topology graph of each core showed identical properties between cores. These results suggest that any region of the Internet defined by the network centrality has a structure with properties the same as the topology of the entire network. Thus, the Internet topology structure exhibits fractal characteristics.